1. Technical Field
The present invention relates to an onboard display device which derives and displays a remaining driving range which is an estimation of how far a vehicle can travel on the remaining electric power in the battery.
2. Related Art
As of recent, electric vehicles, which have batteries that drive an electric motor which powers the vehicle, are becoming commonplace. Japanese Unexamined Patent Application Publication (JP-A) No. 2012-222876 and Japanese Unexamined Patent Application Publication (JP-A) No. 2012-205470 propose a technology to derive a remaining driving range which is an estimation of how far such a vehicle can travel on the remaining electric power in the battery, and display this on a display unit such as an onboard display or the like.
JP-A No. 2012-222876 describes a technology in which an integrated value of power consumption is learned every predetermined period, a remaining driving range is derived based on the learning history, and displayed on a display unit. This technology involves separate learning of power consumed by the driving motor and power consumed by other than the driving motor. Accordingly, if the power to an accessory such as the air conditioner is turned off, the effects of that accessory are subtracted, and an appropriate remaining driving range at that point is immediately derived. JP-A No. 2012-205470 discloses a technology in which a standard remaining driving range in a case of the usage state of the accessories being in a standard state, and a full-load remaining driving range estimated in a case of the usage state of the accessories being in a full-load state, are displayed together on the display unit.
In the technology according to JP-A No. 2012-222876 described above, each time the usage state of accessories changes, such as the air conditioner being turned on and off, the remaining driving range is changed, which means that the display of remaining driving range frequently changes. This may seem annoying to the occupants of the vehicle. Moreover, the occupants cannot tell how much a full load of accessories, such as turning the air conditioner on full power, will shorten the remaining driving range, without actually trying by operating the accessories in that way.
In the technology according to JP-A No. 2012-205470, the standard remaining driving range and full-load remaining driving range are both displayed. However, the occupants cannot tell how much a minimum load of accessories, such as turning the air conditioner off to minimize electric power consumption, will extend the remaining driving range, without actually trying by operating the accessories in that way.